A Queens dad trying to protect fellow straphangers from a deranged man on a Times Square subway platform was hurled onto the tracks by the lunatic and fatally crushed by a train yesterday, cops and witnesses said.

Ki Suk Han, 58, desperately tried to scramble back to the platform as onlookers screamed, shouted and frantically waved their hands and bags in a bid to get the downtown Q train to stop at around 12:30 p.m.